IssueTracker

While -keepclassmembers caused a regression in the original bug, we've added allowsObfuscation to allow even kept fragments to be obfuscated.

This will be available in the upcoming Fragment 1.2.4 and 1.3.0-alpha03.

The new release 1.2.4 now leads to a direct crash on app-start, i.e. when Android tries to inflate any Fragment referenced in the main navigation graph.

Re #5 - please file a new bug with a sample project that reproduces your issue.

This change in 1.2.4 also leads to ClassNotFoundException when a fragment is created by providing a name attribute to a FragmentContainerView if the referenced fragment class name is not explicitly kept and obfuscation is enabled:

<androidx.fragment.app.FragmentContainerView
                ...
                android:name="fullClassName"
                ... />

This, of course, is the expected behavior, but I think it is too much of an API-breaking change for a patch release.

Re #7 - please make sure you've followed the instructions in b/142601969 as otherwise no ProGuard rules are generated for FragmentContainerView referenced classes as per the Fragment 1.2.0 Known Issues.

If you're using Android Gradle Plugin 4.1 Canary 4 or higher and you're not getting your classes properly kept and non-obfuscated when using FragmentContainerView, please file a bug against AAPT.

Re #6: It's essentially https://issuetracker.google.com/issues/142601969 and indeed an API-breaking change. Unfortunately, there's no proper fix for AGP 3.6 nor 4.0, thus one can't update until those are stable. It's unfortunate as other AndroidX libraries start depending on 1.3.4 (such as preferences).